In 1986, Mkele Mbembe was on holiday in Kenya after graduating from
Northwestern University. On a hike through the bush, he came across
a young bull elephant standing with one leg raised in the air. The
elephant seemed distressed, so Mbembe approached it very carefully.
He got down on one knee and inspected the elephant's foot, and found a
large piece of wood deeply embedded in it. As carefully and as
gently as he could, Mbembe worked the wood out with his hunting knife, after
which the elephant gingerly put down its foot. The elephant turned to face
the man, and with a rather curious look on its face, stared at him for
several tense moments.

Mbembe stood frozen, thinking of nothing else but being trampled.
Eventually the elephant trumpeted loudly, turned, and walked away.

Mbembe never forgot that elephant or the events of that day.

Twenty years later, Mbemb was walking through the Chicago Zoo with
his teenaged son. As they approached the elephant enclosure, one of the
creatures turned and walked over to near where Mbembe and his son
Tapu were standing. The large bull elephant stared at Mbembe, lifted its
front foot off the ground, then put it down. The elephant did that
several times then trumpeted loudly, all the while staring at the man.

Remembering the encounter in 1986, Mbembe couldn't help wondering if
this was the same elephant. Mbembe summoned up his courage, climbed
over the railing and made his way into the enclosure. He walked right up
to the elephant and stared back in wonder.

The elephant trumpeted again, wrapped its trunk around one of
Mbembe's legs and slammed him against the railing, killing him instantly.

How did anyone know that Mbembe remembered about the encounter 20 years ago that's why he climbed over the railings when Mbembe was killed instantly?

Well Mbembe was visiting the Zoo with his teenage son Tapu. So had this actually happened, Mbembe might have said something like "Look, look son! That's the same elephant. The one I told you about with the dodgy foot. Wait there for a minute while go over and say hello to it."